Physics Work,Power & Energy Level: High School
A 1.2 kg object moving with a speed of 8.0 m/s collides perpendicularly with a wall and emerges with a speed of 6.0 m/s in the opposite direction . If the object is in contact with the wall for 2.0 ms , what is the magnitude of the average force on the object by the wall ?a) 9.8 kN
b) 8.4 kN
c) 7.7 kN
d) 9.1 kN
e) 1.2 kN
Physics Work,Power & Energy Level: High School
A 3.0 kg mass is dropped from the edge of a 50-m tall building with an initial speed of zero. The mass strikes the ground with a down ward velocity of 25 m/s. how much work is done on the mass by air resistance between the point where it is dropped and the point where it strikes the ground ?a) -0.46 kj
b) -0.53 kj
c) -0.61 kj
d) -0.38 kj
e) -0.81 kj
Physics Work,Power & Energy Level: High School
A particle is acted up on by only two forces, one conservative and one nonconservative as it moves from point A to point B . The kinetic energy of particle at point A and B are equal if .a) The sum of the works of the two forces is zero .
b) the work of the conservative force is equal to the work of the nonconservative force .
c) the work of the conservative force is zero .
d) the work of the nonconservative force is zero .
e) none of the above
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 Current Electricity Level: High School
Find the current through each resistor in the diagram as shown at "click here" .
Physics Electrostatics Level: High School
Find the equivalent capacitance and the charge on each capacitor in the diagram as shown at "click here" , if C1 = 10.0 micro F , C2 = 20.0 micro F, C3 = 30.0 micro F , C4 = 40.0 micro F , and V = 12.0 V .
Physics Ray Optics Level: High School
Where should an object be placed in front of a convex spherical mirror of 15.5 cm focal length in order to get a virtual image with a magnification of one-half ?
Physics Ray Optics Level: High School
A concave spherical mirror has a , focal length of 15.0cm . Where should an object be placed such that the height of the image is a quarter of the height of the object ?
Physics Alternating Current Level: High School
Consider an RLC circuit with R = 10 ohm , L = 0.1 H , and C = 100 micro F . The ac voltage applied is 100 V and a frequency of 60 Hz . Find :
the inductive reactance , capacitive reactance , and the total impedance ;
the current in the circuit; voltage across each component ; and the phase angle
Physics Electrostatics Level: High School
Consider charges q1 = 1x 10^ -7 C , q2 = 2x 10^ -7 C , q3 = 3x 10^ -7 C , and q4 = 4x10^ -7 C placed at four corners of a square of side 1m , Calculate the potential at the centre of the square . If a charge of 5x10^-7 C is placed at the center of the square , what is its potential energy ?
Physics Electrostatics Level: High School
Consider point charges q1 = q2 =2 micro C , q3 = q4 = -2 micro C . Find the electric field intensity at the center of the square as shown in the figure at "click here" . Each diagonal is of length 2 m .
