A reference frame can be moving. To make sure that newtons laws still apply, the reference frame must not be accelerating.
Answer:
<h2>a.The ball's vertical acceleration is downwards.</h2><h2>e.The ball's horizontal acceleration is zero</h2>
Explanation:
We are given that Sarah throws a tennis ball as far as she can.
At the moment the ball reaches its maximum height.
We have to find the true statement if air resistance is neglect.
When air resistance is negligible then the force act on the ball is force due to gravity.
The ball throw vertically then the acceleration act on the ball is acceleration due to gravity.
The value of g=-9.8 m/square sec
It acts on the ball in downward direction .
Therefore, the ball's vertical acceleration is downwards.
The horizontal acceleration is zero because the ball reaches at maximum height then there is no force which act in horizontal direction on the ball.
Therefore, horizontal acceleration of the ball is zero.
Hence, option a and e are true.
Answer: ethanol which will dissolve in both water (a polar solvent) and gasoline (a non-polar solvent)
Explanation:
Answer:
14.2 m
Explanation:
Using conservation of energy:
PE at top = KE at bottom
mgh = ½ mv²
h = v² / (2g)
h = (16.7 m/s)² / (2 × 9.8 m/s²)
h = 14.2 m
Using kinematics:
Given:
v₀ = 16.7 m/s
v = 0 m/s
a = -9.8 m/s²
Find: Δy
v² = v₀² + 2aΔy
(0 m/s)² = (16.7 m/s)² + 2 (-9.8 m/s²) Δy
Δy = 14.2 m
Answer:
method I = 88 chairs
method II = 62 chairs
Explanation:
This problem can be modeled by a system of two linear equations.
Define x as the number of chairs refinished by method I and y by method II
The sum of hours spent on both methods should equal 199 and the sum of total material cost should equal $1226, therefore:
Multiplying the first equation by -18 and adding it to the second equation we can solve for the value of y:
We can now apply the value of y found to the first equation and solve for x:
Therefore, they should refinish 88 chairs with method I and 62 chairs with method II
