Question

A motorist drives north for 35.0 minutes at
85.0 km/h and then stops for 15.0 minutes.
He next continues north, travelling 130 km in
2.00 hours. What is his total displacement
1) 85 km
2) 179.6 km
3) 20 km
4) 140 km​

Answer 1

 

ᴄᴀsᴇ1:

85ᴋᴍᴘʜ =23.611 ᴍᴇᴛᴇʀᴘᴇʀsᴇᴄ

35 ᴍɪɴ=0.583ʜʀ

ᴅɪsᴛᴀɴᴄᴇ ᴛʀᴀᴠᴇʟʟᴇᴅ ɪɴ ғɪʀsᴛ ᴄᴀsᴇ = 0.583x85=49.555

ᴄᴀsᴇ 2:

130 ᴋᴍ ɪɴ 2ʜʀs 

ᴅɪsᴛᴀɴᴄᴇ ᴛʀᴀᴠᴇʟʟᴇᴅ = 130ᴋᴍ

ғɪɴᴀʟʟʏ ᴛᴏᴛᴀʟ ᴅɪsᴛᴀɴᴄᴇ ᴛʀᴀᴠᴇʟᴇᴅ ʙʏ ᴍᴏᴛᴏʀɪsᴛ ɪs = 130+49.555=179.555=179.6

 Explination:

ᴛ1=0.583 ʜʀ

ᴛ2=2 ʜʀ

s1=49.555 ᴋᴍ

s2=130 ᴋᴍ

sɴᴇᴛ=179.6

ᴠ1=23.611ᴍ/s=85ᴋᴍᴘʜ