Explanation:
Distance covered by the particle is given by:
Distance (d) = rate (v) × time (t)
Speed of Mary, v₁ = 50 mph
Speed of Jim, v₂ = 60 mph
It is assumed that, Mary and Jim leave at the same time. After one hour, Jim is 10 miles ahead.
Distance travelled by Jim, d₁ = (60t + 10)
Distance travelled by Mary, d₂ = 50t
The distance between Mary and Jim is greater than or equal to 100 miles.
So, Jim takes is 9 hours more than Mary to cover same distance. Hence, this is the required solution.
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.
Answer:
2.87 km/s
Explanation:
radius of planet, R = 1.74 x 10^6 m
Mass of planet, M = 7.35 x 10^22 kg
height, h = 2.55 x 10^6 m
G = 6.67 x 106-11 Nm^2/kg^2
Use teh formula for acceleration due to gravity
g = 1.62 m/s^2
initial velocity, u = ?, h = 2.55 x 10^6 m , final velocity, v = 0
Use third equation of motion
0 = v² - 2 x 1.62 x 2.55 x 10^6
v² = 8262000
v = 2874.37 m/s
v = 2.87 km/s
Thus, the initial speed should be 2.87 km/s.