The question is incomplete. Here is the entire question.
A jetboat is drifting with a speed of 5.0m/s when the driver turns on the motor. The motor runs for 6.0s causing a constant leftward acceleration of magnitude 4.0m/s². What is the displacement of the boat over the 6.0 seconds time interval?
Answer: Δx = - 42m
Explanation: The jetboat is moving with an acceleration during the time interval, so it is a <u>linear</u> <u>motion</u> <u>with</u> <u>constant</u> <u>acceleration</u>.
For this "type" of motion, displacement (Δx) can be determined by:
is the initial velocity
a is acceleration and can be positive or negative, according to the referential.
For Referential, let's assume rightward is positive.
Calculating displacement:
= - 42
Displacement of the boat for t=6.0s interval is = - 42m, i.e., 42 m to the left.
Using the given formula with v0=56 ft/s and h=40 ft
h = -16t2 + v0t
40 = -16t2 + 56t
16t2 - 56t + 40 = 0
Solving the quadratic equation:
t= (-b+/-(b^2-4ac)^1/2)/2a = (56+/-((-56)^2-4*16*40)^1/2)/2*16 = (56 +/- 24) / 32
We have two possible solutions
t1 = (56+24)/32 = 2.5
t2 = (56-24)/32 = 1
So initially the ball reach a height of 40 ft in 1 second.
Answer:
(D) The weight of the space station and the gravitational force of the space station on the earth.
Explanation:
In both A and B , both the forces act in the same direction ( downwards ) , so they can not be action- reaction force .
In the option C , weight of a astronaut can only be reaction force of gravitational force exerted on the earth by astronaut. Both astronaut and the earth pull each other with equal and opposite force. So option D is correct.
X ray is one of the electromagnetic waves.
As per Clark Maxwell's electromagnetic theory, all the electromagnetic waves move with the velocity of light i.e c= 3×10^8 m/s
In case of electromagnetic waves,the electric field and magnetic field are perpendicular to each other as well as perpendicular to the direction of propagation.The electromagnetic waves exhibit the property of polarisation. Hence they are transverse in nature.
Hence the best statements about X- ray will be-
1- X -rays are electromagnetic waves
2-X-rays are transverse transverse waves
3- X- rays travel at the speed of light.
Daguerreotype is defined as the
first practical photographic process which was introduced in Paris on January
7, 1839. To make the image permanent, Daguerre used salt solution. The result
of his introduced process is a finely defined image with surface which is
delicate. The major benefit of daguerreotype is if the images are correctly
preserved, the pictures could last forever. Aside from this, since it produces superior
quality of outline, it is thus suitable for portraitures.
