The right answer would be
-20t+ 80
There are missing data in the text of the problem (found them on internet):
- speed of the car at the top of the hill:
- radius of the hill:
Solution:
(a) The car is moving by circular motion. There are two forces acting on the car: the weight of the car
(downwards) and the normal force N exerted by the road (upwards). The resultant of these two forces is equal to the centripetal force,
, so we can write:
(1)
By rearranging the equation and substituting the numbers, we find N:
(b) The problem is exactly identical to step (a), but this time we have to use the mass of the driver instead of the mass of the car. Therefore, we find:
(c) To find the car speed at which the normal force is zero, we can just require N=0 in eq.(1). and the equation becomes:
from which we find
Explanation:
Weak nuclear force:
The interaction between the subatomic particles is called weak nuclear force.
The weak nuclear force is one of the four fundamental forces.
The weak nuclear force is effective at very short distance.
The range and relative strength of weak nuclear force is 10⁻¹⁸ m and 10²⁵ with respect to gravitational force respectively
Deuterium is formed due to the fusion of protons and neutrons under the action the weak force.
Example : Beta decay
Electromagnetic force:
The interaction between the charged particles is called electromagnetic force.
The electromagnetic force is one of the four fundamental forces.
The electromagnetic force is effective at long range distance.
The range and relative strength of electromagnetic force is infinity and 10³⁶ with respect to gravitational force respectively
Example : light
Answer:
250 J
Explanation:
Apply the formula:
K = 1/2.m.v²
K = 1/2.5.10²
K = 1/2.5.100
K = 5.50
K = 250 Joules
But, remember that if the speed is accelerating or not, if it is, then we need to know the point in time that the question is asking for the Kinetic Energy.
In this case, I think it is just a constant speed.