Question is missing. Found on google:
<em>"Part A What is the acceleration of the ball? Express your answer to two significant figures and include the appropriate units. </em>
<em>Part B
</em>
<em>What is the net force on the ball during the hit? </em>
<em>Express your answer to two significant figures and include the appropriate units."</em>
Solution:
A) 
The acceleration of the ball is given by
where
v = 12 m/s is the final velocity
u = 0 is the initial velocity (the ball is stationary)
t = 2.0 ms = 0.002 s is the time of contact
Substituting,
B) 
The force on the ball can be found by using Newton's second law:
where
m = 140 g = 0.14 kg is the mass of the ball
is the acceleration
Substituting,
Answer:
the crown was not made of pure gold
Explanation:
Mass of gold = weight in air/ g = 7.84N/10ms-2= 0.784 Kg or 0.8Kg
From Archimedes principle:
Upthrust= weight in air- weight in a fluid
Upthrust= volume × density × g
Note density of water = 1000kgm-3
7.84-6.84= V × 1000kgm-3×10ms-2
V= 1/10000= 1×10-4 m^3
Density = mass/ volume= 0.8/1×10-4
= 8×10^3 Kgm-3
But we know the density of gold to be 19.3 ×10^3 kgm-3
Hence the crown was not made of pure gold
Period: 1/Frequency
1/457 = 0.002188 seconds
Round it to 0.0022 seconds
The answer is D
<h2>
Number of revolutions required to travel 100 yards is 57.</h2>
Explanation:
Diameter of tire,D = 20 inches
Perimeter of tire = πD
Perimeter of tire = π x 20 = 62.8 inches
Distance traveled = 100 yards
1 yard = 36 inches
Distance traveled = 100 x 36 = 3600 inches
In one revolution it travels 62.8 inches.
Number of revolutions required to travel 100 yards is 57.
