A 17 kg child descends a slide 3.5 m high and reaches the bottom with a speed of 1.5 m/s. How much thermal energy due to friction was generated in this process?
initial PE=FinalKE-thermalenergylost
mgh=1/2mv^2-thermalenergy lost.
a 0.145 kg baseball pitched at 39.0 m/s is hit on a horizontal line drive straight back toward the pitcher at 52.0 m/s.if the contact time between bat and ball is 0000.3 s,calculate the average force between the ball and bat during contact.
325J
To calculate the thermal energy due to friction, we need to use the principle of conservation of mechanical energy. This principle states that the total mechanical energy of a system, which includes both kinetic energy and potential energy, is conserved when only conservative forces (like gravity) are acting on the system. However, in this case, the thermal energy due to friction is a non-conservative force, so it converts some of the mechanical energy into thermal energy.
First, let's find the initial potential energy of the child at the top of the slide using the formula:
Potential Energy = mass × gravity × height
where:
mass = 17 kg (mass of the child)
gravity = 9.8 m/s^2 (acceleration due to gravity)
height = 3.5 m (height of the slide)
Potential Energy = 17 kg × 9.8 m/s^2 × 3.5 m
Potential Energy = 578.6 J
Next, we'll find the final kinetic energy of the child at the bottom of the slide using the formula:
Kinetic Energy = 0.5 × mass × velocity^2
where:
mass = 17 kg (mass of the child)
velocity = 1.5 m/s (speed of the child at the bottom of the slide)
Kinetic Energy = 0.5 × 17 kg × (1.5 m/s)^2
Kinetic Energy = 19.125 J
Now, we can find the thermal energy due to friction by subtracting the final kinetic energy from the initial potential energy:
Thermal Energy = Potential Energy - Kinetic Energy
Thermal Energy = 578.6 J - 19.125 J
Thermal Energy = 559.475 J
Therefore, the thermal energy due to friction generated in this process is approximately 559.475 Joules.