Physics Work,Power & Energy Level: High School
A 2.0 kg block is sliding on a horizontal frictionless surface is attached to one end of a horizontal spring (k= 200 N/m) which has its other end fixed . If the block has a speed of 4.0 m/s as it passes through the equilibrium position . What is its speed when it is 20 cm from the equilibrium position ?a) 2.6 m/s
b) 3.1 m/s
c) 3.5 m/s
d) 1.9 m/s
e) 2.3 m/s
Physics Work,Power & Energy Level: High School
A spring (k= 600 N/m) is placed in a vertical position with its lower end supported by a horizontal surface . The upper end is depressed 20 cm , and a 4.0 kg block is placed on the depressed spring . The system is then released from rest . How far above the point of release will the block rise ?46 cm
36 cm
41 cm
31 cm
20 cm
Physics Work,Power & Energy Level: High School
A skier weighing 0.80 kN comes down a frictionless ski run that is circular (R = 30 m) at the bottom as shown in the figure at “click here”. If her speed is 12 m/s at point.A . what is her speed at the bottom of the hill (point B)17 m/s
19 m/s
18 m/s
20 m/s
12 m/s
Physics Work,Power & Energy Level: High School
A 2.0 kg mass is projected from the edge of the top of a 20 m tall building with a velocity of 24 m/s at some unknown angle above the horizontal . Disregard air resistance and assume the ground is level . What is the kinetic energy of the mass just before it strikes the ground ?0.18 kj
0.97 kj
0.89 kj
0.26 kj
0.40 kj
Physics Work,Power & Energy Level: High School
A single conservative force Fx = (6.0x – 12) N (x is in m) acts on a particle moving along the x axis . The potential energy associated with this force is assigned a value of +20 J at x=0 . what is the potential energy at x = 3.0 m ?+11J
+29J
+9.0
-9.0
+20J
Physics Work,Power & Energy Level: High School
A 1.4 kg object moves along the X axis , subject to the potential energy shown in the figure at "click here" . If the object's speed at point B is 2.67 m/s , what are the approximate locations of its turning points ?m (lefthand turning point)
m (righthand turning point)
Physics Work,Power & Energy Level: High School
A 0.2 kg rubber ball is dropped from the window of the building . It strikes the sidewalk below at 30 m/s and rebounds at 20 m/s . Find the change in momentum of the ball as a result of the collision with the side walk ( in kg m/s ) .
Physics Work,Power & Energy Level: High School
The potential energy of a 0.20 kg particle moving along the X axis is given by U (x) = 8x^2-2x^4 where U is in joules and x in meters . When the particle is at x = 10m , what will be its acceleration ?
Physics Work,Power & Energy Level: High School
Assuming an efficiency of 25% for the muscle system in the process of converting food energy into mechanical work , how much energy would be used by a person of mass 75 kg . (weight 165 lb.) in the process of climbing four flights of stairs for a total height of 15 meters ? Find the answer in joules and convert to dietary calories (1 dietary calorie = 4186 joules)
Physics Work,Power & Energy Level: High School
A person pushes a 10 kg cart a distance of 20 meters by exerting a 60 newton horizontal force . The frictional resistance force is 50 newtons . How much work is done by each force acting on the cart ? How much kinetic energy does the cart have at the end of the 20 meters if it started from rest ?
Physics Work,Power & Energy Level: High School
A 2.0 kg block is thrown upward from a point 20 m above Earth's surface . At what height above Earth's surface will the gravitational potential energy of the Earth block system have increased by 500 J ?
Physics Work,Power & Energy Level: High School
As in the figure shown in "click here" a small block of mass m = 0.041 kg can slide along the frictionless loop-the-loop , with loop radius R = 15 cm . The block is released from rest at point P , at height h = 7R above the bottom of the loop . How much work does the gravitational force do on the block as the block travels from point P toa) point Q and
b) the top of the loop? If the gravitational potential energy of the block-Earth system is taken to be zero at the bottom of the loop , what is that potential energy when the block is
c) at point P,
d) at point Q, and
e) at the top of the loop ?
Physics Work,Power & Energy Level: High School
A 66 kg skier starts from rest at height H = 20 m above the end of the ski-jump ramp (as shown in the figure "click here") . As the skier leaves the ramp, his velocity makes an angle of 'theta = 21 degree' with the horizontal . Neglect the effects of air resistance and assume the ramp is frictionless .a) What is the maximum height h of his jump above the end of the ramp ?
b) If he increased his weight by putting on a 10 kg backpack , what would h be ?
Physics Work,Power & Energy Level: High School
A certain crane lifts a load of 1.0 Metric ton through a vertical distance of 25m in 9.0s . If the load is raised at a constant velocity , how much power does the crane supply ? If the load is then dropped a pilling at ground level , how much work can it do on the pilling ?
Physics Work,Power & Energy Level: High School
Two particles , of mass M and 2M respectively , each moving with speed 3 m/s . collide head-on . Find their speeds immediately after the collision if the collision is perfectly inelastic .