Explanation:
Given:
v₀ = 0 m/s
a = 9.8 m/s²
t = 4.7 s
Find: Δy
Δy = v₀ t + ½ at²
Δy = (0 m/s) (4.7 s) + ½ (9.8 m/s²) (4.7 s)²
Δy ≈ 110 m
Answer:
Explanation:
To find Sammy's course you have to add the two velocities (vectors), 18 mph 327º and 4 mph 60º.
To add the two vectors analytically you decompose each vector into their vertical and horizontal components.
<u>1. 18 mph 327º</u>
- Horizontal component: 18 mph × cos (327º) = 15.10 mph
- Vertical component: 18 mph × sin (327º) = - 9.80 mph
<u>2. 4 mph 60º</u>
- Horizontal component: 4 mph × cos (60º) = 2.00 mph
- Vertical component: 4 mph × sin (60º) = 3.46 mph
<u>3. Addition:</u>
You add the corresponding components:
To find the magnitude use Pythagorean theorem:
<u>4. Direction:</u>
Use the tangent ratio:
Find the inverse:
Answer: KE = 25 J
Explanation: You must use the formula
KE = 1/2 m v²
to solve this problem.
KE = 1/2 (10 Kg) (5 m/s)
KE = 1/2 (50 kgm/s)
KE = 25 J
Explanation:
Half-life is the time taken for a radioactive material to decay to half its original composition:
Original mass = 48g
Half- life = 2hr
After four half lives;
Initially: 48g
First halving 24
Second halving 12
Third halving 6
Fourth halving 3
After second half life, we would have 12g
At fourth halving, we would have 3g
In empty space probably means, there is no force on the ball.
(This assumption is not quite correct since there is still the force of gravity between the ball and the astronaut, but this force is very very small and can be neglected.)
Assuming there is no force on the ball, Newtown's 1st law says: When viewed in an internal frame of reference, an object either remains at rest or continues to move at a constant velocity, unless acted upon by a force.
This means:
If there is no force on the ball, there will be no acceleration on the ball either.
If the acceleration is zero, the velocity of the ball never changes.
