Answer:
Evan drive at speed = 81.67 m/hr
Explanation:
Normal speed of Evan = 70 m/hr
Time taken by Evan to visit his grandmother = 35 min = hr
Distance covered by Evan = =
= miles
According to the problem, one day Evan was running 5 minutes late. So, the time Evan has to visit his grandmother is 30 mins.
To reach on time, Evan should be drive at the speed :
Speed =
=
= 81.67 m/hr
Answer:
F = 1.6 × 10⁻¹⁵ N
Explanation:
Given: V= 5.0 × 10⁴ m/s, B = 0.20 T, q = 1.60 × 10⁻¹⁹ C and θ = 90°
To Find: F = ?
Solution:
we have a Formula for this question
F = q ( V x B) ∴ x is used for cross product
F= q V B sin θ
F = 1.60 × 10⁻¹⁹ C × 5.0 × 10⁴ m/s × 0.20 T sin 90°
F = 1.6 × 10⁻¹⁵ N
Explanation:
When an object moves up in the air, kinetic energy (KE) is converted into potential energy (PE). When kinetic energy is exhausted, the object will stop rising and begin to descend. But the KE lost is all converted to PE.
1. Both kinetic energy when the gymnast leaves the trampoline and the potential energy achieved at the highest point are the same and equal to
PE(at highest point) = KE (when leaving trampoline)
= (mv^2)/2 = 60 kg * (7 m/s)^2 /2 = 1470 joules
2. Since the PE at the highest point is 1470 and equals mgh, we have
60*9.81*h = 1470 joules
Solve for h
h= 1470/(60*9.81) = 2.50 m
F=ma, approximating that gravity is 10 m/s
F=6*10
F=60