Answer:
a. 8.96 m/s b. 1.81 m
Explanation:
Here is the complete question.
a) A long jumper leaves the ground at 45° above the horizontal and lands 8.2 m away.
What is her "takeoff" speed v
0
?
b) Now she is out on a hike and comes to the left bank of a river. There is no bridge and the right bank is 10.0 m away horizontally and 2.5 m, vertically below.
If she long jumps from the edge of the left bank at 45° with the speed calculated in part a), how long, or short, of the opposite bank will she land?
a. Since she lands 8.2 m away and leaves at an angle of 45 above the horizontal, this is a case of projectile motion. We calculate the takeoff speed v₀ from R = v₀²sin2θ/g. where R = range = 8.2 m.
So, v₀ = √gR/sin2θ = √9.8 × 8.2/sin(2×45) = √80.36/sin90 = √80.36 = 8.96 m/s.
b. We use R = v₀²sin2θ/g to calculate how long or short of the opposite bank she will land. With v₀ = 8.96 m/s and θ = 45
R = 8.96²sin(2 × 45)/9.8 = 80.2816/9.8 = 8.192 m.
So she land 8.192 m away from her bank. The distance away from the opposite bank she lands is 10 - 8.192 m = 1.808 m ≅ 1.81 m
Answer:
-24.28571 rad/s²
29.57239 revolutions
3.91176 seconds
52.026478 m
Explanation:
= Tangential acceleration = -6.8 m/s²
r = Radius of wheel = 0.28
= Initial angular velocity = 95 rad/s
= Angle of rotation
= Final angular velocity
t = Time taken
Angular acceleration is given by
The angular acceleration is -24.28571 rad/s²
The number of revolutions is 29.57239
The time it takes for the car to stop is 3.91176 seconds
Linear distance
The distance the car travels is 52.026478 m
Answer:
the money that would be saved is $13.14.
Explanation:
Given;
power consumed by the light bulb, P = 100 W = 0.1 kW
time of running the bulb, t = 3 hours for 365 days = 1,095 hours
cost rate of power consumption, C = $0.12 per kWh
Energy consumed by the light bulb for the given days;
E = Pt
E = 0.1 kW x 1,095 hr
E = 109.5 kWh
Cost of energy consumed = 109.5 kWh x $0.12 / kWh
= $13.14
Therefore, the money that would be saved is $13.14.
Feet and inches or millimeters or centimeters or meters or miles or kilometers
Answer:
Explanation:
Refractive Index: It is a measure to find how fast the light travels through a medium. It is ration of the speed of light in vacuum to speed of light in the medium. Speed of light is not constant and varies depending on the density of the medium.
In vacuum the speed of light is 300000 km/s and is denoted by c. When the light beam enters any medium the speed will decrease. Here it is given that the speed in plastic is v. Thus the refractive index(n) is given as:
It is a dimensionless no.
