Answer:
Mary's average speed is 0.42 meters/second.
Explanation:
Mary's total travel was 250 meters and the elapsed time was 10 minutes, equivalent to 600 seconds.
d = displacement = 80 meters + 125 meters + 45 meters = 250 meters
t = time = 10 minutes . 60 seconds/minute = 600 seconds
We can obtain now the average speed:
s = average speed = displacement / time = 250 meters / 600 seconds ≅ 0.4167 ≅ 0.42
Answer:
Explanation:
Let the balls collide after time t .
distance covered by falling ball
s₁ = v₀ t + 1/2 g t²
distance covered by rising ball
s₂ = v₀ t - 1/2 g t²
Given ,
s₁ + s₂ = D
D = v₀ t + 1/2 g t² + v₀ t - 1/2 g t²
= 2v₀ t
t = D / 2v₀
s₂ = v₀ t - 1/2 g t²
= v₀ x D / 2v₀ - (1/2) x g x D² / 4v₀²
= D / 2 - gD² / 8 v₀²
weight of 30 Kg object= 300 N
Explanation:
Weight= m I
m= mass=30 kg
I= gravitational filed strength= 10 N/kg
weight=30 (10)
weight=300 N
Answer:
Both are only physical changes
Explanation:
A physical change is a change that does not involve or alter the chemical composition of the substances involved. Physical changes form no new substance and can be easily separated into individual constituents. Example of physical changes are change in state, boiling, melting etc.
According to this question, two processes were given as follows:
1. mixing chocolate syrup into milk
2. rain forming in a cloud
These two processes are similar in the sense that they are both examples of physical changes.
Answer:
35.3 N
Explanation:
U = 0, V = 0.61 m/s, s = 0.39 m
Let a be the acceleration.
Use third equation of motion
V^2 = u^2 + 2 as
0.61 × 0.61 = 0 + 2 × a × 0.39
a = 0.477 m/s^2
Force = mass × acceleration
F = 74 × 0.477 = 35.3 N
