The speed of a car during a trip is represented in the graph. compare distance and displacement at four hours into the trip.
a) the distance traveled is 300 km.
b) distance is 300 km and displacement is 0 km.
c) distance is 300 km/hour and displacement is 300 km.
d) both distance traveled and displacement are 300 km.

The answer to your question is: D.

Explanation:

Distance refers to the amount of space between two points, it is a scalar quantity.

Displacement refers to the space between two points, measure from the minimum path linking them, it is a vector quantity.

I'm not agree with these answers, because the total distance  is approximately 500km.

A) The distance traveled is 300 km.  This answer is not correct.

B) Distance is 300 km and displacement is 0 km.  This answer is not correct because the displacement is also 500 km.

C) Distance is 300 km/hour and displacement is 300 km. 300 km/h is a measure of speed not of distance, this option is wrong.

D) Both distance traveled and displacement are 300 km. I think this is the correct answer because distance and displacement measure the same. but I think both measure 500 km.

A) The distance traveled is 300 km.

Explanation:

Since the graph represents the distance time graph so we don't have any idea about the path length of the car.

So here we can not comment about the displacement of the motion of the car

so here we can see from the graph that

at t = 0  the position of the car is x = 0

now when car will reach at t = 4 hour

the distance of the car is

d = 300 km

so we can say that distance covered by the car will be

d = 300 km

the velocity you are looking for is made up of two parts: horizontally velocity, vh, and its vertical velocity, vv. the actual velocity of the ball will be these two parts added together, and because velocity is a vector then they will need to be added vectorially.  

neglecting air resistance etc etc.,  

the horizontal velocity component will be constant (because there is no accelerating force in the horizontal direction.  

vh = 8 ms-1  

the vertical velocity component has an accelerating force: 'g'.  

using v = u +at where a = g = 9.81 ms-2.  

the vertical component of velocity, vv = 0 + gt = vv =9.81 x 2  

vv = 19.62 ms-1 . the zero appears because the virtical component of velocity at time t=0 is zero. remember, the ball was thrown horizontally.  

how fast it will be moving (it actual path (being a parabola )) will be the vector sum of these two.  

adding vectorally gives: -  

v = sqr root (8^2 + 19.62^2) = sqr root(64+384.9) = 21.18 or 21.2 ms-1

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.