No force is necessary to keep a moving object moving (in a straight line at a constant speed).
Answer:
1.48kg
Explanation:
Here,
potential energy (P.E) = 29j
height (h) = 2m
acceleration due to gravity(g) =
mass(m) = ?
we know,
P.E = mgh
or, 29 = m×9.8×2
or, 29/19.6 = m
or,m = 1.48kg
Choice-'a' is a slippery, misleading, ambiguous statement,
but it's less wrong than any of the other choices on this list.
Answer:
fr = ½ m v₀²/x
Explanation:
This exercise the body must be on a ramp so that a component of the weight is counteracted by the friction force.
The best way to solve this exercise is to use the energy work theorem
W = ΔK
Where work is defined as the product of force by distance
W = fr x cos 180
The angle is because the friction force opposes the movement
Δk = –K₀
ΔK = 0 - ½ m v₀²
We substitute
- fr x = - ½ m v₀²
fr = ½ m v₀²/x
Answer:
Explanation:
Force between two charges is given by the following expression
F = Q₁ and Q₂ are two charges and d is distance between two.
.1 =
If Q₁ becomes three times , force will become 3 times . Hence force becomes .3 N in the first case.
Force F = .3 N
If charge becomes one fourth , force also becomes one fourth .
F=
= .025 N.