Answer:
The time it takes the ball to stop is 0.021 s.
Explanation:
Given;
mass of the softball, m = 720 g = 0.72 kg
velocity of the ball, v = 15.0 m/s
applied force, F = 520 N
Apply Newton's second law of motion, to determine the time it takes the ball to stop;

Therefore, the time it takes the ball to stop is 0.021 s.
Answer:
1.) Micrometres screw gauge
2.) Tape rule.
Explanation:
Given that the diameter and the length of a thin wire, approximately 1m in length, are measured as accurately as possible.
what are the best instruments to use ?
To measure the diameter of a thin wire, the best instrument to use is known as micrometres screw gauge.
And to measure the length of a thin wire up to 1 m, the measuring device can be tape rule or long metre rule.
Answer:
6.71 × 10^8 mi/hr
Explanation:
Light is usually defined as an electromagnetic wave that is comprised of a definite wavelength. It is of both types, visible and invisible. The light emitted from a source usually travels at a speed of about 3 × 10^8 meter/sec. This speed of light is commonly represented by the letter 'C'.
To write it in the metric system, it has to be converted into miles/hour.
We know that,
1 minute = 60 seconds
60 minutes = 1 hour
1 kilometer = 1000 meter
1 miles = 1.6 kilometer
Now,
= 
= 1.08 × 10^12 m/ hr (meter/hour)
= 
= 6.71 × 10^8 mi/hr (miles/hour)
Thus, the value for speed of light (C) in metric unit is 6.71 × 10^8 mi/hr.