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There are two ice skaters with mass 80 kg and 32 kg at rest on ice initially. When one of them (heavier skater) pushes off against the other (lighter skater), and the heavier skater starts to move with a speed of 3 m/s. What is the speed of the lighter skater in m/s? Note that the distinguish the positive direction from the negative direction, and the heavier skater moves in the positive direction.
During a time period of 0.04 s, a force of average strength of 300 N is applied. How much is the change in momentum of the ball in kg m/s. First calculate the impulse and then the change in momentum.
A railroad car with a mass of 12,000 kg collides with another with a mass of 20,000 kg that is at rest initially and they couple after the collision. If the car that comes to collide initially has a speed of 12 m/s, what is their speed together after the collision in m/s.
Many gas appliances such as ovens and heaters use a small flame to ignite the main burner .In order to make sure that the small flame is burning, a temperature-measuring device is inserted into the flame. What is the most suitable device to use?
An astronaut drops a feather from 1.2m above the surface of the moon. If the acceleration of gravity on the moon is 1.62m/s2 downward how long does it take the feather to hit the moon’s surface?
Find the force necessary to keep the toy car in equilibrium. The mass of the toy is 5kg and the inclination of the plane is 30°. Friction is neglected.
A force of 20N pulls two carts tied together with a string. The carts with masses 3kg and 4kg, respectively, run on a smooth level surface. Find :
a. The acceleration of the 4kg cart
b. The acceleration of the 3kg cart
c. The tension on the string connecting the two carts.
A lift is reported to operate at 75% efficiency. If the lift can raise a load through a height of 30m using a 230V, 15A supply, calculate how long it will take to raise a load of 1000Kg.
A motor and gearbox system are used to raise a load from the ground to the roof. The load weighs 100Kg and the motor fed from supply of 110v and draws 15A. If the roof is 25m above the ground, calculate: a) The PE of the load when it has been raised, b) The amount of electrical energy used in that time
A student eats a dinner containing 2000Calories of energy. He wishes to do an equivalent amount of work in the gymnasium by lifting a 10Kg object. How many times must he raise the object to expand this much work? Assume that he lies to his back and raises it a distance of 0.5m each, and the effort done to let the weight down is 50% of the effort done to raise it.
