JL

John Lawrence

Numerade Educator
Researcher

Biography

PhD student in Physics, studying high energy particle physics.

Education

John has not yet added their education credentials.

Educator Statistics

Numerade tutor for 4 years
12 Students Helped

Topics Covered

Mastering Motion: Achieving Efficiency Along a Straight Line
Mastering Newton's Laws: Tips for Applying Them Effectively

John's Textbook Answer Videos

1

John's Quick Ask Videos

01:54
Physics 101 Mechanics

On the horizontal plane is a pair of parallel, conducting wires separated by a distance L. The left ends are connected to a resistor R as shown in the figure.
Sliding frictionlessly on the wires is a conducting bar. The resistances of the wires and bar are negligible. A uniform magnetic field B of a certain intensity B is applied perpendicular to the page.

L = 2.3 m
R = 13 ̐
The conducting bar is pulled to the right at a constant speed v = 13 m/s.
As the bar moves, a constant current I = 1.3 A flows in the direction indicated by the arrow.

What is the magnitude B of the magnetic field?
(a) B = 0.57 T
(b) B = 1.14 T
(c) B = 0.8 T
(d) B = 0.37 T
(e) B = 3.93 T
The direction of the magnetic field
(a) cannot be determined.
(b) is into the page.
(c) is out of the page.
02:03
Physics 101 Mechanics

02:22
Physics 101 Mechanics

A 23-kg child slides down a slide at a park, as shown below. The coefficient of kinetic friction between the child and the slide is 0.400.

θ = 43°

a) Draw a free body diagram of the child. Be sure to include all forces and clearly label them.
b) What is the magnitude of the normal force on the child?
c) What is the magnitude of the friction force on the child?
d) What is the magnitude of the net force on the child?
e) If the child starts from rest, what is their speed after sliding for 1.5 seconds?
04:47
Physics 101 Mechanics

02:26
Physics 101 Mechanics

02:46
Physics 101 Mechanics

A cannonball is fired with an initial speed v0 at an angle of 30° above the horizontal from a height of 36.4 m above the ground. The projectile strikes the ground with a speed of 1.1v0. Find v0. (Ignore any effects due to air resistance.)

Question 6:
True or false (ignore any effects due to air resistance): When a projectile is fired horizontally, it takes the same amount of time to reach the ground as an identical projectile dropped from rest from the same height.
True
False

Question 7:
True or false-When a projectile is fired from a certain height at an upward angle, it takes longer to reach the ground than does an identical projectile dropped from rest from the same height.
True
False

Question 8:
True or false-When a projectile is fired horizontally from a certain height, it has a higher speed upon reaching the ground than does an identical projectile dropped from rest from the same height.
True
False
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