Physics Work,Power & Energy Level: High School
A 400-N child is in a swing that is attached to ropes 2.00 m long . Find the gravitational potential energy of the child-Earth system relative to the child’s lowest position whena) the ropes are horizontal
b) the ropes make a 30.0 degree angle with the vertical
c) the child is at the bottom of the circular arc .
Physics Work,Power & Energy Level: High School
A 2.00 g block is attached to a spring of force constant 500 N/m as in the figure 7.10 . The block is pulled 5.00 cm to the right of equilibrium and released from rest . Find the speed of the block as it passes through equilibrium ifa) the horizontal surface is frictionless
b) the coefficient of friction between block and surface is 0.350 .
Physics Work,Power & Energy Level: High School
A force F = (4xi + 3yj) N acts on an object as the object moves in the x direction from the origin to x = 5.00 m . find the work W = F . dr done on the object by the force
Physics Work,Power & Energy Level: High School
The force acting on a particle is Fx = (8x-16) N ,where x is in meters .a) Make a plot of this force versus x from x = 0 to x = 3.0 m .
b) From your graph , find the net work done by this force on the particle as it moves from x = 0 to x = 3.00 m .
Physics Work,Power & Energy Level: High School
collision
In a perfectly elastic collision ,a) momentum is conserved but not kinetic energy .
b) momentum and kinetic energy are conserved .
c) momentum is not conserved but kinetic energy is .
d) neither momentum nor kinetic energy is conserved .
Physics Work,Power & Energy Level: High School
Elastic Pottial E When a spring with a spring constant K is compressed by a distance x , the potential energy of the spring ,
a) increases by k x
b) increases by ½ kx^2
c) decreases by k x
Physics Work,Power & Energy Level: High School
Collision
A 50 g ball of putty moving with a velocity of 3.0 m/s collides head on with a stationary mass of 50 g and sticks to it . Find the velocity of the mass and putty after the collision .
Physics Work,Power & Energy Level: High School
power
1 watt is the same as (1 Js or 1 Nm or 1 kgm^2/over s^2 or 1 kgm^2 /over s^3).
Physics Work,Power & Energy Level: High School
A 70 kg cart is pushed for 50 m with a constant velocity upon a 45 degree frictionless incline . find the work done on the cart . (assume g = 10 m/s^2) .
Physics Work,Power & Energy Level: High School
A 100 kg object is pulled vertically upward 5 cm by a rope with an acceleration of 1m/s^2 . Find the work done by the tension force in the rope (assume g = 10 m/s^2)
Physics Work,Power & Energy Level: High School
Conservation of energy
A simple pendulum with a bob of mass 250 g and length 2.0 m is allowed to fall from a horizontal position . What is the speed of the bob as it passes the lowest point ?
Physics Work,Power & Energy Level: High School
energy
Two objects have the same kinetic energy . if the speeds of the objects are in the ratio 3:1 the ratio the ratio of their masses is ?
Physics Work,Power & Energy Level: High School
Power
The power rating of an engine is 5.0 kW. What is the horsepower of the engine ?
Physics Work,Power & Energy Level: High School
collision
A 3 kg bowling ball traveling with a velocity of 3 m/s collides head on with another bowling ball of the same mass traveling with a velocity of -2 m/s . If the collision is perfectly elastic the velocity of the bowling balls after the collision are ?
Physics Work,Power & Energy Level: High School
Collision
An object with a mass of 2 kg traveling with a velocity of 3 m/s collides head on and elastically with a stationary object of mass 0.5 kg . The velocity of the 2 kg mass after the collision is ?