A 13-kg sled is moving at a speed of 3.0 m/s. At which of the following speed will the sled have twice as much kinetic energy?
4.2 m/s
Answer:
Q1 = 7.25*10^(-16) C
Explanation:
We are given;
electric field strength = (1 x 10^5 N/C
drag force (F) = 7.25 x 10^(-11) N
The question says it's moving with constant velocity. This means that he particle is in equilibrium and not accelerating.
Columbs law force of attraction or repulsion between two charges is given as;
F=(KQ1Q2)/r²
Now, electric field strength is given as the formula;(K*Q2)/r², thus plugging the relevant values gives us;
7.25 x 10^(-11) N= (1 x 10^(5) N/C)Q1 Q1 = 7.25 x 10^(-11) /(1 x 10^(5))
Q1 = 7.25*10^(-16) C
the football player has speed
Answer:
Its mechanical energy is the same.
Explanation:
If forces are only conservative, the mechanical energy will be the same.
It can be different if energy get transformed in another kind of energy like elastic energy for example, although the amount of energy is always the same.
If we just have mechanical energy not geting transformed we have:
Em=K+U
Em: Mechanical energy
K: Kinetic energý
U: Potential energy
Then if Kinetic energy decreases 10J, Potential energy will grow up 10J to keep the same amount of mechanical energy.
Answer:
0.084 kg
Explanation:
I = 0.80 N-s (East wards) = 0.80 i N-s
u = 3.8 m/s = - 3.8 i m/s
v = 5.7 m/s = 5.7 i m/s
Let m be the mass of bat.
I = m (v - u)
0.8 i = m ( 5.7 i + 3.8 i)
0.8 i = m x 9.5 i
m = 0.084 kg
