Friction is a force. A resistance force that tries to slow down and stop objects in motion. The difference between friction and air resistance is that friction acts on surfaces. For example, if I were skateboarding on a rough surface, more friction would occur so I would travel slower. If I were skareboarding on ice, I would go faster because there is much less friction to slow me down. Hope that helps:)
Answer:
The power of the pump is 337.5 W.
Explanation:
Power is the rate of transfer of energy or the rate at which work is done. It is measured in watts (W).
Power = 
But the energy here is the kinetic energy (K.E), which is the energy possessed by a moving body or object.
K.E = 
m
where m is the mass = 90 kg and v is the velocity = 15 m/s.
K.E = × 90 × 
= 10125 Joules
K.E = 10125 J = 10.125 KJ
So that the power of the pump when t = 30 s is;
Power = 
= 337.5 W
The power of the pump is 337.5 W.
The correct answer is A.
A power station works on the principle of boiling water to create steam, which turns a turbine, generating a potential difference in a transformer with the magnets. The transformer is connected to a circuit, which hence induces a current, generating power.
Answer:
Δx=vt−21at2
Explanation:
We can figure out which kinematic formula to use by choosing the formula that includes the known variables, plus the target unknown.
In this problem, the target unknown is the acceleration as the cyclist slows down.
Assuming the initial direction of travel is the positive direction, our known variables are
t=0.5s
v=10km/h
Δx=2m
Since we don't know the initial velocity (Vo), and we are not asked to find (Vo) we could use the kinematic formula that is missing (Vo) to solve for the target unknown, A
Δx=vt−21at
