The statement above is FALSE.
The right hand rule is used in physics to predict the direction of the force on a charged object moving in a MAGNETIC FIELD. The right hand rule is used to relate the relationship between the magnetic field and the forces that are exerted on the moving objects in the field. Using the right hand rule, for a positively charged object that is moving in an electric field, the pointer finger will point in the direction the charged object is moving, the middle finger will point in the direction of the magnetic field and the thumb will point in the direction of the magnetic force that is pushing the charged object.
Answer:
3.5 hours
Explanation:
Speed = distance/time
Let the distance that Fiora biked at 20 mi/h through be x miles and the time it took her to bike through that distance be t hours at 20 mi/h
Then, the rest of the distance that she biked at 14 mi/h is (112 - x) miles
And the time she spent biking at 14 mi/h the rest of the distance = (6.5 - t) hours
Her first biking speed = 20 mph = 20 miles/hour
Speed = distance/time
20 = x/t
x = 20 t (eqn 1)
Her second biking speed = 14 mph = 14 miles/hour
14 = (112 - x)/(6.5 - t)
112 - x = 14 (6.5 - t)
112 - x = 91 - 14t (eqn 2)
Substitute for x in (eqn 2)
112 - 20t = 91 - 14t
20t - 14t = 112 - 91
6t = 21
t = 3.5 hours
x = 20t = 20 × 3.5 = 70 miles.
(112 - x) = 112 - 70 = 42 miles
(6.5 - t) = 6.5 - 3.5 = 3 hours
Meaning that she travelled at 20 mi/h for 3.5 hours.
let the height of the person with marshmallow on her head be "h"
consider the motion of the marshmallow after it is dropped from bridge.
Y₀ = initial position of the marshmallow above the ground = 5.71 m
Y = final position of marshmallow on head of person = h
v₀ = initial velocity of the marshmallow = 0 m/s
a = acceleration due to gravity = - 9.8 m/s²
t = time of travel for marshmallow = 0.921 sec
Using the kinematics equation
Y = Y₀ + v₀ t + (0.5) a t²
inserting the values
h = 5.71 + 0 (0.921) + (0.5) (-9.8) (0.921)²
h = 5.71 - 4.16
h = 1.55 m
When an object gains electrons it gains a negative charge.
C. Negative
