Work is done when a force acts on an object AND the object moves in the direction of the force.
-- <em>Pulling a trailer up a hill. YES. </em> The trailer is moving in the direction of the pulling force.
-- Carrying a box down a corridor. No. The box is not moving in the direction of gravity (down) OR in the direction of your arm (down the corridor).
-- Suspending a heavy weight with a strong chain, No. There's a force (gravity) acting on the weight, but the weight is not moving at all.
-- Pushing against a locked door. No. There's a force (your muscles) acting on the door, but he door is not moving at all.
Cerebellum: controls balance and muscle coordination; located caudal to the cerebrum in the sheep brain. ... Gray matter: areas of the brain and spinal cord containing neuronal cell bodies, dendrites, and unmyelinated axons. Found in the cerebral cortex of the brain and inner area of the spinal cord
Answer:
3.2 m/s
Explanation:
Given:
Δx = 1000 m
v₀ = 23 m/s
a = -0.26 m/s²
t = 76 s
Find: v
This problem is over-defined. We only need 3 pieces of information, and we're given 4. There are several equations we can use. For example:
v = at + v₀
v = (-0.26 m/s²) (76 s) + (23 m/s)
v = 3.2 m/s
Or:
Δx = ½ (v + v₀) t
(1000 m) = ½ (v + 23 m/s) (76 s)
v = 3.3 m/s
Or:
v² = v₀² + 2aΔx
v² = (23 m/s)² + 2(-0.26 m/s²)(1000 m)
v = 3.0 m/s
Or:
Δx = vt − ½ at²
(1000 m) = v (76 s) − ½ (-0.26 m/s²) (76 s)²
v = 3.3 m/s
As you can see, you get slightly different answers depending on which variables you use. Since 1000 m has 1 significant figure, compared to the other variables which have 2 significant figures, I recommend using the first equation.
Law of conservation of momentum
67*x=4.2*5.6
Answer:
c) 0.16 m/s2
Explanation:
The computation of the acceleration during the first km of travel is shown below
Given that
Final velocity = v = 42 m/s
Initial velocity = u = 0 m/s
Distance = 5.6km
Based on the above information, we need to apply the following formula
As we know that
= 0.1575 m/s ^2
hence, the correct option is c. 0.16 m.s^2
